Here's the trend chart for the year to date.
As you can see, the shift comes about a week ago. It is mainly reliant on polls from three organizations: ABC/WaPo, Ipsos/Reuters and somewhat surprisingly Rasmussen. And it's just recent. So you really need more data to have real confidence that this is a new direction in the campaign as opposed a mere blip.
But the trend is backed up by a series of other trends that have become very visible over the last few weeks. One example is the favorability rating of both candidates. Until quite recently Romney was the only Republican contender with a net positive favorability rating. But since the beginning of year his net favorability number, according to the TPM Poll Average, has ballooned to more than a 17 point deficit. In contrast, President Obama's net favorability rating is a net positive 5 points according to the TPM Poll Average.
Next we have what is likely the most important metric of the campaign: President Obama's Job Approval rating. (Job Approval rating is different from favorability.) Here President Obama has been underwater for most of the last two years, with a couple brief exceptions tied to major news events. His disapproval peaked during the debt ceiling debacle. But it's been tracking up ever since. And he appears to be close to moving back into positive territory. Our trend analysis still has him just above one in negative territory. But over the last few days several polling organizations have had him in positive territory for the first time in months or years.
Here's the trend for the last 24 months.
The bigger picture seems to be driven by two basic factors: Obama being lifted by a rising economy and a series of negative stories about Romney (gaffes, Bain, 15% tax rate, questions about core beliefs) that are making the public like him less the more they see him. Regardless of the situation in the primaries, if Romney can't bet everything on a bad economy, he's in serious need of a Plan B for November.